Can Dietary Approaches Completely Resolve Crohn’s Disease?

What’s performing best in evidence-based treatment for this inflammatory bowel disease is straight-forward dietary advice that keeps symptoms in remission. 

Studies indicate that a diet rich in plants is a superior way to keep Crohn's disease in remission and possibly to prevent it in the first place. Shutterstock

The mystery of Crohn’s disease is rapidly evaporating under the weight of research showing its relationship to the standard American diet.

Plenty of evidence connects certain foods to damage in the lining of the gastrointestinal tract. Could that mean that there’s a way to resolve Crohn’s symptoms by simply changing what we eat?

Several studies in Japan have evaluated and elevated plant-based diets, particularly for lowering the relapse of Crohn’s disease symptoms. Newer studies offer more evidence pointing to the role of food, including the connection between Crohn’s disease and ultra-processed food, as well as yeast.

The rise of inflammatory bowel disease (IBD), such as Crohn’s and ulcerative colitis, marches to the beat of industrialization. Some might argue that socio-technological developments explain the uptick in diseases such as IBD, but growing research finds that processed food is a key contributor to the explosion of these diseases in the developed world.

As a study in early 2023 in the Journal of Clinical Medicine pointed out, “the prevalence is also growing in newly industrialized countries in Africa, Asia, and South America mirroring the growing incidence of IBD observed in the 1990s in Western countries occurring with urbanization and the rapid socioeconomic development.”

These findings seem to offer credibility to the popular phrase “You are what you eat,” although not everyone is convinced that diet alone offers a cure. Still, there’s growing hope that Crohn’s patients can benefit from a holistic approach, addressing diet among other foundational principles, for an anti-inflammatory lifestyle. Conventional options—drug therapy and surgery—represent a tremendous cost and don’t always resolve the underlying inflammation.

The Origins of this Modern Disease

Nearly 1 in 100 Americans are diagnosed with IBD, according to the Crohn’s and Colitis Foundation. Crohn’s—named after one of the researchers who discovered it—was first described in a landmark report in the Journal of the American Medical Association in October 1932.

The authors of that report proposed a disease of the terminal ileum—the most distal part of the small intestine—although today it’s believed that Crohn’s can affect any part of the gastrointestinal tract. That’s one way in which it’s distinct from ulcerative colitis, which only affects the colon and rectum. The report also explained Crohn’s as affecting mainly young adults (still true, although it can be diagnosed in all ages) and having an inflammatory state associated with tissue death and scarring.

They also noted that the mucosa in these patients developed ulcers and connective tissue reactions and often led to the narrowing of the intestinal lumen, as well as the formation of multiple fistulas. This transforms a normally smooth mucosal layer into a lumpy, devoted passageway that’s more difficult for food to pass through.

It may not occur all in one place. Crohn’s is known for spotty inflammation occurring anywhere from mouth to anus with painful symptoms that vary widely depending on where the disease is manifesting. Some symptoms include diarrhea, nausea, vomiting, loss of appetite, weight loss, intense abdominal pain, and rectal bleeding.

In autoimmune diseases such as Crohn’s, the immune system turns on an excessive and prolonged inflammatory response. Inflammation causes tissue swelling, heat, redness, and pain. It can be useful in the short term for clearing infections from the body.

Beyond Bad Genes

IBD is believed to affect genetically susceptible people whose symptoms are triggered by environmental risk factors. Often, this is referred to as “epigenetic,” meaning that what we’re exposed to can turn certain genes on and off. Research in IBD and its link to genetics and environmental risk factors, particularly diet, has been accelerating over the past couple of decades.

Two genetic studies in the past five years have brought an understanding of why Crohn’s patients may have a harder time recovering from gut insults.

A mechanism was discovered in 2018 by which a genetic change to a protein produced by the C1ORF106 gene can alter the junctions that connect cells to form the lining of the human gut, resulting in impaired intestinal barrier function, or “leaky gut.” Some IBD patients also overproduce a protein called plasminogen activator inhibitor 1 (PAI-1), which can interfere with gut healing by blocking a protein called tissue plasminogen activator.

How genetics works together with environmental risk factors is somewhat of a mystery. However, a 2019 commentary in The Permanente Journal pointed out that the Western diet is the most ubiquitous risk factor for IBD.

“Representative environmental factors such as smoking, breastfeeding, nonsteroidal anti-inflammatory drugs, antibiotic use in childhood, oral contraceptives, and appendectomy do not correlate with disease onset in most patients with IBD,” the authors wrote.

Could Eating Determine Disease Onset?

Research published in September conducted a meta-analysis of five studies published between 2020 and 2022 involving more than 1 million people. Over those years, 3,000 were diagnosed with IBD. Those eating a diet of ultra-processed food and even minimally processed food had higher odds of developing Crohn’s disease than those who ate a diet lower in processed food. Results were published in Clinical Gastroenterology and Hepatology.

Another study recently published highlights how yeasts—potentially both the commensal fungal gut residents and the dietary intake of yeasts—can drive immune cell reactivity in patients with Crohn’s. Published in Nature Medicine, the article states that the findings invite testing to see whether the removal of yeast antigens, anti-fungal therapy, and/or a yeast-free diet could help lower inflammation and put the disease in remission.

“From my experience, it never comes down to one thing like that, hardly ever,” said Dr. Amy Beard, a family physician, certified functional practitioner, and dietitian. “I would love to know what is behind the response as well, other than just genetics, because in my experience, there’s a whole host of other lifestyle and environmental mediators behind why yeast is an issue.”

Dr. Beard told The Epoch Times that yeast could simply appear to be triggering symptoms because it’s concurrent with an imbalance in the gut microbiome—the community of trillions of bacteria, viruses, fungi, and other microscopic organisms that help us digest food. Targeting only yeast would be like arresting a witness who’s at the scene of the crime without looking at all the other evidence, she said.

“I love that this research has really honed into this yeast response,” she said. “I seriously doubt this is going to be the ticket. I wonder about what is making yeast the issue.”

One likely possibility is diet.

A shift in eating habits, particularly westernized diets deficient in dietary fiber, has been shown to shrink gut microbial diversity. This often indicates dysbiosis, or imbalance, which is often associated with more disease-causing bacteria in the gut.

For instance, commonly used food emulsifiers and artificial flavor enhancers have been shown to promote the growth and pathogenic action of certain strains of Escherichia coli (E. coli), harmful bacteria found in the microbiota of patients with Crohn’s, according to a 2019 review article in Nutrients. Likewise, a diet high in animal products and low in fiber also induces rapid microbiota changes associated with IBD, while diets high in soluble plant polysaccharides—associated with microbial diversity—have been noted to curb E. coli. production.

There’s a growing list of small but revealing studies showing that those Crohn’s patients who increase plant consumption and lower meat in their diets fare better in the active stage of the disease and in preventing flares.

Plant-based Diets Coming Out on Top

A small study of 22 hospitalized Crohn’s patients in Japan a decade ago revealed that 100 percent of patients who maintained a semi-vegetarian diet—16 patients—stayed in remission for a year with only one person experiencing a relapse in the second year. There were two relapses among the six patients eating an omnivore diet.

“Remission was maintained in 15 of 16 patients (94%) in the SVD [semi-vegetarian diet] group vs two of six (33%) in the omnivorous group,” the study reads.

A semi-vegetarian diet consisted of large quantities of brown rice, miso soup, pickled vegetables, and green tea; daily consumption of eggs, plain yogurt, vegetables, fruits, legumes, and potatoes; occasional milk, algae, and other plant foods; fish once per week; and meat only once every two weeks.

Published in the World Journal of Gastroenterology, the study also encouraged healthy habits such as not smoking, regular physical activity, moderate or no use of alcohol, and eating on a regular schedule with no eating between meals.

In 2018, the study’s lead author—Dr. Mitsuro Chiba, a gastroenterologist and researcher in Japan—wrote a commentary explaining that even when used in conjunction with medication, a plant-based diet reduces remission rates. The most common drug for Crohn’s is infliximab, an infusion therapy that’s ineffective for 30 to 40 percent of patients. A semi-vegetarian diet alone has been shown to curb the need for additional treatment with infliximab or other drug therapies, he said.

The Toll of Medical Therapy

Infliximab can be costly, but patients whose symptoms can’t be managed may end up needing more aggressive therapies such as hospitalization and surgery to remove sections of the intestines.

A study analyzing the financial burden of Crohn’s found that nearly half of the 243 patients studied required surgery within 10 years of diagnosis, with about half of that group finding themselves getting second and third procedures. Published in the journal Inflammatory Bowel Diseases in 2017, the study notes that the cost of Crohn’s in the United States is estimated at $10.9 billion to $15.5 billion per year.

More than half of the cohort of 243 patients accounted for 77.5 percent of the total cost burden; those with the worst disease burden had a median cost of $187,579.

Simple Strategies Proven to Help

On the other hand, there are more cost-effective strategies that appear beneficial—lowering stress, reducing alcohol consumption, increasing vitamin D levels, and reducing exposure to environmental toxins among them.

“Stress is a big one, and I’ve seen that in a lot of Crohn’s patients and ulcerative colitis,” Dr. Beard said. “Stress—whether it’s physical, emotional, mental—you will see a lot of the flairs occurring during these times because of the way it’s modulating and mediating the immune system.”

Specifically, she recommended the following:

• Eat real, organic food. (Interestingly, she noted that her patients seem to do better on a more meat-based diet and less vegetables.)
• Aim for more restorative sleep, which can help lower stress.
• Avoid alcohol, smoking, and drugs, including prescriptions. “Alcohol is a big no-no for Crohn’s. You’re just asking for trouble. Get off as many pharmaceuticals as you can, especially the ones we know are going to impact your gut, the acid suppressors, the birth controls, the antibiotics, the NSAIDs,” Dr. Beard said.
• Spend more time outside for benefits extending beyond vitamin D—the “feel-good” hormones we get mostly from sun-to-skin exposure.
• Move your body daily without overdoing exercise.
• Replace toxic chemicals for your yard, skin, and cleaning.
• Drink plenty of water to make sure you’re adequately flushing the liver and kidneys.

While various specific factors may contribute to IBD, it’s best to focus on the most likely and obvious contributors, according to Dr. Beard.

“Before people start chasing zebras, I think they need to make sure they are doing what we call the fundamentals of functional medicine,” she said.